The Remote Request Substitution bit is a dominant bit ("0") in the CAN XL
frame. As some CAN XL controllers support to access this bit a new
CANXL_RRS value has been defined for the canxl_frame.flags element.
To read/write the Remote Request Substitution (RRS) bit in the CAN XL
frame the CAN_CTRLMODE_XL_RRS has to be enabled in CAN driver.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
include/uapi/linux/can.h | 5 ++++-
include/uapi/linux/can/netlink.h | 1 +
ip/iplink_can.c | 6 ++++++
3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
index 229a77ff..513d3d75 100644
--- a/include/uapi/linux/can.h
+++ b/include/uapi/linux/can.h
@@ -180,20 +180,23 @@ struct canfd_frame {
};
/*
* defined bits for canxl_frame.flags
*
- * The canxl_frame.flags element contains two bits CANXL_XLF and CANXL_SEC
+ * The canxl_frame.flags element contains three bits CANXL_[XLF|SEC|RRS]
* and shares the relative position of the struct can[fd]_frame.len element.
* The CANXL_XLF bit ALWAYS needs to be set to indicate a valid CAN XL frame.
* As a side effect setting this bit intentionally breaks the length checks
* for Classical CAN and CAN FD frames.
+ * To read/write the Remote Request Substitution (RRS) bit in the CAN XL
+ * frame the CAN_CTRLMODE_XL_RRS has to be enabled in CAN driver.
*
* Undefined bits in canxl_frame.flags are reserved and shall be set to zero.
*/
#define CANXL_XLF 0x80 /* mandatory CAN XL frame flag (must always be set!) */
#define CANXL_SEC 0x01 /* Simple Extended Content (security/segmentation) */
+#define CANXL_RRS 0x02 /* Remote Request Substitution */
/* the 8-bit VCID is optionally placed in the canxl_frame.prio element */
#define CANXL_VCID_OFFSET 16 /* bit offset of VCID in prio element */
#define CANXL_VCID_VAL_MASK 0xFFUL /* VCID is an 8-bit value */
#define CANXL_VCID_MASK (CANXL_VCID_VAL_MASK << CANXL_VCID_OFFSET)
diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index 416e2feb..19267678 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -104,10 +104,11 @@ struct can_ctrlmode {
#define CAN_CTRLMODE_TDC_AUTO 0x200 /* FD transceiver automatically calculates TDCV */
#define CAN_CTRLMODE_TDC_MANUAL 0x400 /* FD TDCV is manually set up by user */
#define CAN_CTRLMODE_XL 0x800 /* CAN XL mode */
#define CAN_CTRLMODE_XL_TDC_AUTO 0x1000 /* XL transceiver automatically calculates TDCV */
#define CAN_CTRLMODE_XL_TDC_MANUAL 0x2000 /* XL TDCV is manually set up by user */
+#define CAN_CTRLMODE_XL_RRS 0x4000 /* XL enable RRS bit access */
/*
* CAN device statistics
*/
struct can_device_stats {
diff --git a/ip/iplink_can.c b/ip/iplink_can.c
index 8dc9229b..9fe9ae6c 100644
--- a/ip/iplink_can.c
+++ b/ip/iplink_can.c
@@ -40,10 +40,11 @@ static void print_usage(FILE *f)
"\t[ presume-ack { on | off } ]\n"
"\t[ cc-len8-dlc { on | off } ]\n"
"\t[ tdc-mode { auto | manual | off } ]\n"
"\t[ xl { on | off } ]\n"
"\t[ xtdc-mode { auto | manual | off } ]\n"
+ "\t[ xlrrs { on | off } ]\n"
"\n"
"\t[ restart-ms TIME-MS ]\n"
"\t[ restart ]\n"
"\n"
"\t[ termination { 0..65535 } ]\n"
@@ -123,10 +124,11 @@ static void print_ctrlmode(enum output_type t, __u32 flags, const char* key)
print_flag(t, &flags, CAN_CTRLMODE_TDC_AUTO, "TDC-AUTO");
print_flag(t, &flags, CAN_CTRLMODE_TDC_MANUAL, "TDC-MANUAL");
print_flag(t, &flags, CAN_CTRLMODE_XL, "XL");
print_flag(t, &flags, CAN_CTRLMODE_XL_TDC_AUTO, "XL-TDC-AUTO");
print_flag(t, &flags, CAN_CTRLMODE_XL_TDC_MANUAL, "XL-TDC-MANUAL");
+ print_flag(t, &flags, CAN_CTRLMODE_XL_RRS, "XL-RRS");
if (flags)
print_hex(t, NULL, "%x", flags);
close_json_array(t, "> ");
@@ -333,10 +335,14 @@ static int can_parse_opt(struct link_util *lu, int argc, char **argv,
CAN_CTRLMODE_XL_TDC_MANUAL;
} else {
invarg("\"xtdc-mode\" must be either of \"auto\", \"manual\" or \"off\"",
*argv);
}
+ } else if (matches(*argv, "xlrrs") == 0) {
+ NEXT_ARG();
+ set_ctrlmode("xlrrs", *argv, &cm,
+ CAN_CTRLMODE_XL_RRS);
} else if (matches(*argv, "restart") == 0) {
__u32 val = 1;
addattr32(n, 1024, IFLA_CAN_RESTART, val);
} else if (matches(*argv, "restart-ms") == 0) {
--
2.45.2
